- The Atlantic is calm now, but there are signs of activity to watch out for as July begins.
- Hurricane and tropical storm activity increases slightly in the western Atlantic and the Gulf of Mexico.
- The area where tropical development occurs expands east and north.
- The second month of the hurricane season has produced some notable storms.
The hurricane season has already got off to a strong start, and although the Atlantic is calm now, changes are anticipated in July.
A huge cloud of dust tracked the Atlantic to the United States in the past week, and two additional columns of dust are moving through the Atlantic basin. These feathers, or the Saharan air layer (SAL) typically create sinking air and an increase in vertical wind shear (the change in winds with height), both of which are hostile to the tropical cyclone development.
Typical origin and tracks of July tropical cyclones in the Atlantic basin.
As a result, there has not been much tropical development in recent times. The tropical waves that have formed have generally made it south of the dust areas when they emerged in the African Atlantic.
Current satellite and Saharan dust
Dust feathers from the Sahara are common at this time of year, but generally decrease around August.
There are indications that some changes are coming in the first week of July, Michael Ventrice Tropic Expert Notes from The Weather Company.
The amount of dust is likely to decrease, and combined with higher level changes, conditions may become more conducive or favorable for a disturbance to become a tropical cyclone in the main Atlantic development region, or the area between Africa and the Caribbean Sea. , in the next 10 days.
There may also be an opportunity for another system to form closer to the east coast, although it is likely to continue to the northeast away from the United States, according to Ventrice.
Conditions may then return to a less favorable environment for tropical activity in the Atlantic in late July or early August, Ventrice notes.
(PLUS: We’ve already seen 6 unusual things happening this hurricane season)
What is generally expected in July
Tropical activity generally remains slow in July, but there is a slight rebound and potential development areas begin to expand further east into the Atlantic Ocean, including the main development region.
From 1950-2019, 68 named storms formed in the Atlantic in July, or an average of about one named storm in July each year. Incidentally, the first named storm of the Atlantic season will have formed in the second week of July in a typical season.
An average of a July hurricane develops every two to three years. July 2019 saw a named storm, Hurricane Barry, which made landfall in Louisiana. Two hurricanes formed in July 2018, Beryl and Chris, which was unusual.
Major hurricanes, Category 3 or stronger on the Saffir-Simpson Hurricane Wind Scale, in July they are rare. Only five major hurricanes have developed during the second month of the hurricane season since 1950.
Tropical storm (red) and hurricane (white) frequency per month in the Atlantic basin.
A subtle shift east
July is a month of transition. Formation areas extend east to include more of the Atlantic Ocean east of the Lesser Antilles.
Tropical waves, one of the seeds for the development of tropical storms, was defined a little better in July. That’s one reason we look further east in the second month of the hurricane season.
The Gulf of Mexico remains somewhat active in July, although the western Caribbean Sea shrinks somewhat as cold fronts become much less frequent.
Development can also occur from an area north of Hispañola to an area north of the Bahamas. Those storms can linger on the east coast and churn up high waves causing beach erosion and rip currents, curl or harmlessly resort to the open Atlantic, or, in more rare cases, make landfall on parts of the east coast.
Only five July hurricanes have made landfall along the east coast since 1950, none of which reached the highest hurricane strength.
Recent activity from July
There have been notable storms in July, in addition to Hurricane Barry that made landfall on the Gulf Coast in 2019, in the past 15 years.
In 2018, Hurricane Beryl became the second oldest recorded hurricane to form in the main development region. Hurricanes that form on the eastern edge in early July are unusual.
Hurricane Arthur swept across eastern North Carolina with storm flooding and high winds during the July 4, 2014 vacation.
Hurricane Alex made landfall in July 2010 in northern Mexico. Its torrential rain flooded the Rio Grande Valley and Monterrey, Mexico.
On July 3, 2008, Tropical Storm Bertha became the oldest eastern storm in the Atlantic basin in the satellite era (since 1966). Bertha was also the longest-running July storm on record when it lasted 17 days in the open waters of the Atlantic Ocean.
Also in July 2008, Category 2 Hurricane Dolly made landfall in South Texas.
Named points of origin for storms in July and current water temperatures.
The record 2005 hurricane season He was very active in July. Five named storms formed that year.
After Hurricane Cindy hit southeast Louisiana, Hurricane Dennis was, at the time, the strongest hurricane on record in the Atlantic basin in July. It made landfall in the Florida Panhandle.
Just six days after Dennis made landfall, Hurricane Emily became the only Category 5 July hurricane on record in the Atlantic basin. It stirred in the Caribbean Sea before hitting Cancun and Cozumel, Mexico.
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